Cat's tails are an important part of their body language, and they use them to communicate with other cats. A cat's tail movements can convey a variety of messages, such as aggression, friendliness, curiosity, and fear. When a cat's tail is held low, it can indicate that the cat is feeling threatened or scared. When a cat's tail is held high, it can indicate that the cat is feeling confident and assertive. A cat's tail can also be used to show interest in another cat, as a cat may twitch its tail when it is interested in another cat.